Question

Two circuits have coefficient of mutual induction of 0.09 henry. Average e.m.f. induced in the secondary by a change of current from 0 to 20 ampere in 0.006 second in the primary will be

• A. 120 V
• B. 80 V
• C. 200 V
• D. 300 V

Answer 1

Answer: (D)

300 V

Answer 2

$e = M\frac{di}{dt} = 0.09 \times \frac{20}{0.006} = 300\mspace{6mu} V$